var dengLu =document.querySelector('.dengLu');
var account =document.querySelector('.account');
var password =document.querySelector('.password');
var tip_one =document.querySelector('.tip_one');
var tip_two =document.querySelector('.tip_two');
var first = document.querySelector('.first');
var second =document.querySelector('.second');
account.onclick = function(){
      first.style.borderColor = 'red';
      account.onfocus = function(){
        //   alert('a');
        account.onblur = function(){
            first.style.borderColor = 'black';
        };
      };
};
password.onclick = function(){
      second.style.borderColor = 'red';
};